Question

find the value of 14 cos square theta + 14 cos square ( theta +90°)?​

Answer 1

Answer:

14cos(2θ)

Step-by-step explanation:

$14 \cos^{2} ( \alpha ) + 14 \cos ^{2} ( \alpha + \frac{\pi}{2} )$

$= 14 \cos^{2} ( \alpha ) - 14 \sin ^{2} ( \alpha )$

as, cos(π/2+θ)= - sin(θ)